The TLDR from Wolfram's announcement:
1. It is not a theory of everything - as he says- but a path to get to one
2. It's possible to define notions of time, causality, or space using transformations between graphs
3. Atm one can't even recover, say, Newtonian physics using this

new language. Having sth like that would have been quite impressive!I bet that gets done eventually
4. A priori it makes sense that with sufficient abstraction anything gets represented; the merit of what Wolfram did is to hint at specific ways in which to derive phys. meaning

Is this the right way to get to a theory of everything? . It's not like we have succeeded so far, so why not try ¯\\_(ツ)_/¯

If one then wants to be sneaky, one can look at the past success of the cellular automata way of thinking presented in NKS. Some things came out of it https://writings.stephenwolfram.com/2012/05/its-been-10-years-whats-happened-with-a-new-kind-of-science/ But not a revolution that I recall some hoped when the book was out

I bet we'll see a lot of interesting graph-based art though!

(To clarify, he says that -it is not a theory of everything-, not that it is; he's not being misleading)

@cmuratori also has a good thread https://twitter.com/cmuratori/status/1250116047585210369